These data represent the elevation of the Earth's land surface in meters, relative to sea level. Positive values are height above sea level, negative values below sea level. The data are formatted as a single-channel 16-bit integer (two byte, long) signed raw binary file, with big-endian byte order and no header. Dimensions are 86400 columns (width, x) by 43200 lines (height, y).The coordinates of the upper-left hand corner of the first pixel is 180 degrees West, 90 degrees North. Grid spacing is 0.004166667 degrees per pixel. The data are in the cylindrical equidistant (geographic, Platte-Carre) projection, utilizing the WGS-84 datum.These elevation data are derived from the <a href="ftp://e0srp01u.ecs.nasa.gov/srtm/version2/SRTM30" target="outlink">Shuttle Radar Topography Mission 30-arcsecond data</a> (SRTM30) and the <a href="http://nsidc.org/data/nsidc-0082.html" target="outlink">Radarsat Antarctic Mapping Project Digital Elevation Model Version 2</a> (RAMP2).We recommend using visualization software to view the file. Although it is possible to import the file into Photshop CS and later, Photoshop will not read the signed data correctly: elevation values above sea level start at 0, while negative elevations "wrap" to values near white (65535), which is sea-level. Sensor: Terra/MODIS.